Robert Irwin’s girlfriend Rorie Buckey leads the birthday tributes to him as he celebrates his 20th birthday… amid rumours he’s about to propose: ‘You’re my everything’

Rorie Buckey kicked off birthday tributes to Robert Irwin by waving goodbye to her friend as he celebrated his 20th birthday on Friday.

The 19-year-old, who is Heath Ledger's niece, shared a photo to her Instagram Story of her boyfriend walking along the sand as she looked out into the distance.

'Congratulations to the most radiant, beautiful person. You are my everything,” she wrote.

Rorie also shared a sweet photo of the couple on her page and expressed her love for Robert.

'Happy 20th birthday to my partner in crime and best friend. I love you,” she added.

Meanwhile, Irwin's sister Bindi, 25, paid tribute to Robert by posting two sweet photos on Instagram to commemorate their time together.

The first photo from 2008 shows Bindi towering over a young Robert, while a more recent photo from 2008 shows them smiling for the cameras again.

'Now I'm standing on my toes to take a picture with you. Happy birthday to the best. 20 years and a lifetime of adventures ahead of you – remember you can always call your sister. I love you,” she wrote alongside the photo.

Robert's mother Terri, 59, also celebrated her son leaving his teenage years by sharing a photo of young Robert driving through the outback with her and looking at a huntsman spider on the roof of their Jeep.

Terri wrote some precious words next to the adorable images.

'Congratulations Robert. How come you're already 20? Thank you for making every day special,” she began.

“You have always marveled at every experience and adventure, and your happiness brings light to my soul.

'Always maintain your curiosity and enthusiasm, because it is a true gift to have such a passion to enjoy life the way you do. I feel incredibly blessed to share the journey with you. I am indeed a happy mother. I love you now and forever.”

And Robert's brother-in-law Chandler Powell, 27, shared a sweet tribute to the Wildlife Warrior by posting a photo of Robert posing up a storm with Bindi and Chandler at the Australia Zoo on the Sunshine Coast.

'Happy twentieth birthday to my brother-in-law. From surfing to reptile spotting to running around with Grace,” he began.

'We're having so much fun. I can't wait to see what the next twenty years bring!'

It comes after Robert and Rorie became Instagram official in August, following months of rumors they were dating.

Rorie reportedly completed an Irwin-approved “wildlife warrior boot camp” before she and Robert became an official couple.

Woman's Day claimed last month that Rorie had to win over the family by being willing to go into nature.

The pair are currently in a long-distance relationship, with Robert based at the Australia Zoo in Queensland, while Rorie is in Perth.

The 18-year-old shared a photo to her Instagram Story of her friend walking along the sand as she looked into the distance

Robert is reportedly planning to pop the question to his girlfriend Rorie.

According to New Idea magazine, the 20-year-old could propose when his girlfriend visits him in Africa in the coming months while he films I'm A Celebrity.

“Everyone is convinced he wants to pop the question when they're in Africa,” said an insider.

'Robert is crazy about her and is planning something unforgettable when he formally asks her to marry him. They both know it's part of their plans, so he's come up with special ways to make it a surprise.”

The source went on to say that Robert and Rorie take their relationship “very seriously” and are planning a future together.

Rorie also shared a sweet photo of the couple and expressed her love for Robert. 'Happy 20th birthday to my partner in crime and best friend. I love you,” she added

Robert and Rorie, the niece of legendary Australian actor Heath Ledger, have a lot in common and both grew up in the public eye after suffering the devastating loss of a family member.

Heath was at the top of his Hollywood career when he was found dead of an accidental drug overdose in January 2008.

Robert's father Steve Irwin, known to the world as the 'Crocodile Hunter', died on September 4, 2006 at the age of 44, after being pierced in the chest by a stingray.

Robert and Rorie became Instagram official in August, after months of rumors that they were dating